here in my location its not harmful to people with DID. there are special circumstances \things that have to be considered but once addressed its perfectly safe for someone with DID here in my location.

here where I am is that dissociation is a reaction to a trigger. if the patient is calm and not triggered then no dissociation happens.

they achieve this in my location by having many sessions discussing what is going to happen, when and how.

then when its time a sedative/anesthesia (just like when someone has surgery done) is given. the sedative/anesthesia ensures the patient is calm and sleepy, and medically unconscious.

then they are hooked up to the ECT equipment.

then the ECT is administered.

then after the medically induced seizure (ECT causes an epilepsy like seizure) ends the patient is taken to a recovery room, where they sleep off the anesthesia.

when they wake up they are a bit disorented\foggy minded, numb, emotionless, not sure what happened. a family member or friend drives them home where they finish sleeping or continuing on with their life.

since you posted that you dissociated before it was administered, that tells me that maybe they didnt take the time to discussing procedure with you and that you were triggered by something to do with the treatment.

my suggestion talk with your treatment providers, they can adjust the sedative/anesthesia. maybe they will even give you a sleep aid or tranquilizer a few hours before the appointment so that you are not triggered before the ECT treatment even begins. I know someone that gets a valium 2 hours before his ECT. by the time he gets there he is happy go lucky, punch drunk or how ever you want to say it.